3D Planning System Research Articles

Orthodontic-orthognathic combined case management in postgraduate orthodontic and oral maxillofacial surgery programs.

With the development of three-dimensional (3D) image, the 3D virtual surgical planning (VSP) system has been broadly used in the treatment planning of orthodontic-orthognathic cases. This study aimed to understand the current education status regarding the use of orthodontic-orthognathic surgical planning tools in the postgraduate orthodontic and oral and maxillofacial surgery (OMFS) programs in North America. An electronic multiple-choice survey was sent via email with 2-week and 1-month follow-ups, requesting anonymous participation of program directors/department chairs from all postgraduate orthodontic and OMFS programs in North America. Responses were collected directly on Qualtrics for analysis. The response rate was 25.68% for orthodontic and 34.34% for OMFS programs. Two-dimensional traditional surgical planning (TSP) at initial treatment planning and 3D VSP right before surgery were most commonly utilized in both specialty programs. All responded postgraduate OMFS programs utilized VSP, yet 26.32% of responded orthodontic programs did not utilize VSP. For the surgical outcomes, fewer orthodontic programs were highly satisfied than OMFS programs. More orthodontic programs warranted secondary surgery at a higher rate due to the unsatisfied outcome. Additionally, the orthodontic programs that did not use VSP showed higher unsatisfied surgical outcomes than the programs that used VSP. Moreover, there were discrepancies between orthodontic and OMFS programs regarding the perceived level of collaboration of each other on the surgical planning for the patients. There were discrepancies between orthodontic and OMFS programs regarding the utilization of VSP, treatment outcomes satisfaction, and perceived level of collaboration on surgical planning for the patients.

Impact of dose distribution by a 3D planning system for brachytherapy with 198Au grains for head and neck cancer.

There has been no study in which the correlation between clinical results and dosimetry based on a 3D treatment planning system in patients with 198Au grains for head and neck cancer was evaluated. Thirty-two patients who were treated with 198Au grains for head and neck cancer were reviewed. Twenty-five patients were treated with brachytherapy alone and seven patients were treated with a combination of brachytherapy and neoadjuvant external beam radiation therapy. With a median observation period of 60 months, the 5-year local control rate was 82.9%. V85Gy of CTV in patients with local recurrence tended to be lower than that in patients without local recurrence (p = 0.07). The maximum dose of the keratinized gingiva in patients in whom bone exposure occurred was significantly higher than that in patients in whom bone exposure did not occur (p = 0.001). Dose distribution with 198Au grains can predict local control and late adverse events.

Pre-selection blade size choice for the microsurgical clipping of cerebral artery aneurysms: A numerical study

BackgroundBrain strokes comprise the third leading cause of death worldwide. Microsurgical clipping is recognized as being one of the most effective approaches to the treatment of brain aneurysms. The incomplete closure of the distal-side aneurysm neck is the most common cause of the persistent filling of the dome. Since the diameter of the neck increases when the neck of the aneurysm is squeezed closed by the blades of the clip, the blades should be correspondingly longer. This study provided an assessment of whether the presurgical selection of clips using a 3D planning system is feasible in terms of selecting the most suitable clip for aneurysm occlusion. MethodsThe computational model was created based on computer tomography data obtained from nine brain aneurysms. The closing of the aneurysm was provided in two steps. The first the length of the blades used for closing corresponded to the length of the aneurysm neck as confirmed by the radiological measurements. The second the length of the blades was adjusted according to stage one, so as to determine the minimum required for the closure of all the gaps in the interior space of the aneurysm neck. ResultsNo differences were detected between the radiological measurement of the aneurysm neck size and the measurements obtained from the reconstructed stereolithographic 3D models. It was observed that the size of the aneurysm neck increased following clipping by 40% to 60% of its original size. The larger the aneurysm neck, the greater the deformation of the aneurysm. ConclusionFirstly, the 3D reconstruction of CT/MRI data did not result in any loss of accuracy and the measurement of the neck of the aneurysm was the same for both of the methods employed. The second, and more important, outcome was that the deformation of the neck of the cerebral aneurysm is at least 1.4x greater than its original size. This information is essential in terms of the pre-selection of the size of the clip.

Clinical application of artificial intelligence-assisted three-dimensional planning in direct anterior approach hip arthroplasty

PurposeThe objective of this study was to investigate the efficacy of an artificial intelligence-assisted 3D planning system (AIHIP) in total hip arthroplasty by direct anterior approach and assess the reliability of the AIHIP preoperative program in terms of both interobserver and intraobserver agreement.MethodsA retrospective analysis was conducted on patients who underwent unilateral primary THA via direct anterior approach from June 2019 to March 2022. Participants were randomly assigned to receive either the AIHIP system (n = 220) or the 2D template (control group) (n = 220) for preoperative planning. The primary outcome aimed to evaluate the correspondence between the prosthesis selected intro-operation and the one planned preoperatively, as well as to calculate the intraclass correlation coefficient (ICC). Secondary outcomes included operation time, intraoperative blood loss, fluoroscopy times, Harris hip score (HHS), lower limb length difference (LLD), femoral offset (FO), and bilateral femoral offset difference.ResultsNo significant differences were observed in gender, age, body mass index (BMI), aetiology, and American Society of Anesthesiologists (ASA) score between the two groups. Both planning methods exhibited good intraobserver agreement for component planning (ICC: 0.941–0.976). Interobserver agreement for component planning was comparable between the two methods (ICC: 0.882–0.929). In the AIHIP group, the accuracy of acetabular cup and femoral stem prosthetics planning significantly improved, with accuracies within the size range of ± 0 and ± 1 being 76.8% and 90.5% and 79.5% and 95.5%, respectively. All differences between two groups were statistically significant (p < 0.05). Patients receiving AIHIP preoperative planning experienced shorter operation times, reduced intraoperative blood loss, fewer fluoroscopy times, and lower leg length discrepancy (LLD) (p < 0.05). Moreover, they demonstrated a higher Harris hip score (HHS) at three days post-surgery (p < 0.05). However, no significant differences were found in femoral offset (FO), difference of bilateral femoral offsets, and HHS at 1 month after the operation.ConclusionUtilizing AIHIP for preoperative planning of direct anterior approach THA can significantly enhance the accuracy of prosthetic sizing with good reliability, decrease operation time, reduce intraoperative blood loss, and more effectively restore the length of both lower limbs. This approach has greater clinical application value.

Do the sizes of total hip arthroplasty implants match between 3D planning software and 2D templating?

IntroductionThe use of three-dimensional (3D) planning before a total hip arthroplasty (THA) procedure is becoming increasingly popular as it offers several theoretical benefits: better restoration of a patient's anatomy, fewer intraoperative problems, and lower THA cost. It is said to be more accurate than two-dimensional (2D) planning, but as far as we know, no study has investigated how well the implant sizes match between 3D and 2D planning for a surgeon who is just starting to use 3D planning. Consistent implant sizes would make it easier for a surgeon to transition from one system to another. This led us to conduct a retrospective comparative study to: (1) compare how well the implant sizes match between a 3D planning system and a 2D planning method (conventional radiography using templates); (2) determine if the sizes planned on the 3D system match the implants that were used in the patient; (3) determine if the sizes planned with the 2D method match the implants that were used in the patient. HypothesisThere is a good match in the implant sizes between the 3D and 2D planning. MethodsA retrospective observational, single-surgeon study was done with patients who underwent THA between January 2019 and September 2021 at a single teaching hospital. For each patient, the size of the THA implants was planned preoperatively in 3D using proprietary software (Optimized Positioning System™, Corin) and 2D templating. These patients were the first to be operated on by this surgeon based on 3D planning. ResultsForty-nine patients were included. The implant size matched exactly between the two planning methods for 20% (10/49) of cups [one size larger with 3D in 35% of hips (17/49) and two sizes larger in 20% of hips (10/49)], for 53% (26/49) of femoral stems [one size smaller with 3D in 53% of hips (26/49)] and for 14% (7/49) of complete THA implant systems (cup, femoral stem, femoral head). The size planned in 3D was the same as the cup size implanted in 51% (25/49) of hips, as the femoral stem size in 65% (32/49) and as the complete THA system in 22% (11/49). The cup was within one size in 88% (43/49) of hips and the femoral stem was within one size in 98% (48/49) of hips. The size planned in 2D was the same as the cup size implanted in 45% (22/49) of hips, as the femoral stem size in 63% (32/49) and as the complete THA system in 18% (9/49). The cup was within one size in 86% (42/49) of hips and the femoral stem was within one size in 96% (47/49) of hips with 2D templating. There was no statistically significant difference in the size matching between the 2D and 3D techniques for either the implanted cup (p=0.5) or the implanted femoral stem (p=0.8). ConclusionThere is a poor match between the implant sizes determined by 3D and 2D planning. Based on our findings, the shift from 2D templating to 3D planning must be done gradually given the learning curve associated with 3D systems. Level of evidenceIII; comparative retrospective study.

Is a Novel Fluoroscopic Intraoperative Reference System Superior to Conventional Management for Distal Radius Fracture Reduction? A Propensity-matched Comparative Study.

Is a Novel Fluoroscopic Intraoperative Reference System Superior to Conventional Management for Distal Radius Fracture Reduction? A Propensity-matched Comparative Study.

The role of 3-dimensional preoperative planning for primary total hip arthroplasty based on artificial intelligence technology to different surgeons: A retrospective cohort study.

Preoperative planning with computed tomography (CT)-based 3-dimensiona (3D) templating has been achieved precise placement of hip components. This study investigated the role of the software (3-dimensional preoperative planning for primary total hip arthroplasty [THA] based on artificial intelligence technology, artificial intelligence hip [AIHIP]) for surgeons with different experience levels in primary THA. In this retrospective cohort study, we included patients, who had undergone THA with the help of the AIHIP, and matched to patients, who had undergone THA without the help of the AIHIP, by age and the doctor who operated on them. The subjects were divided into 4 groups, senior surgeon (Chief of Surgery) with AIHIP group, senior surgeon without AIHIP group, junior surgeon (Associate Chief of Surgery) with AIHIP group and junior surgeon without AIHIP group. The general data, imaging index, clinical outcomes and accuracy of stem size prediction and cup size prediction were retrospectively documented for all patients. There was a significant difference in discrepancy in leg length (P = .010), neck-shaft angle (P = .025) and femoral offset (P = .031) between the healthy side and the affected side, operation duration (P < .001), decrease in hemoglobin (Hb) per 24 hours (P = .046), intraoperative radiation exposure frequency (P < .050) and postoperative complications (overall P = .035) among the patients in junior surgeon group. No significant differences were found between senior surgeon groups with respect to discrepancy in leg length (P = .793), neck-shaft angle (P = .088)and femoral offset (P = .946) between the healthy side and the affected side, operation duration (P = .085), decrease in Hb per 24 hours (P = .952), intraoperative radiation exposure frequency (P = .094) and postoperative complications (overall P = .378). The stem sizes of 95% were accurately estimated to be within 1 stem size, and 97% of the cup size estimates were accurate to within 1 cup size in senior surgeon group with AIHIP. A total of 87% stem sizes were accurately estimated to be within 1 stem size, and 85% cup sizes were accurate to within 1 cup size in junior surgeon group with AIHIP. In conclusion, our study suggests that an AI-based preoperative 3D planning system for THA is a valuable adjunctive tool for junior doctor and should routinely be performed preoperatively.

Long-term results of chemoradiotherapy with elective nodal irradiation for resectable locally advanced esophageal cancer in three-dimensional planning system.

We evaluated the long-term results of definitive chemoradiotherapy (CRT) with elective nodal irradiation (ENI) using a three-dimensional (3D) planning system for resectable, locally advanced esophageal squamous cell carcinoma (LA-ESCC). This retrospective study included 65 patients with LA-ESCC who started CRT between 2006 and 2017. Patients with Stage I-IV LA-ESCC according to the Union for International Cancer Control TNM classification (eighth edition) were included. In stage IV, only supraclavicular lymph node (LN) metastasis was included. All patients received radiotherapy with ENI and concurrent chemotherapy with platinum and 5-fluorouracil. The median age of the patients was 70years (range 52-83years). Stage I, II, III, and IV diseases were observed in 3 (5%), 28 (43%), 22 (34%), and 12 patients (18%), respectively. The median prescription dose was 66Gy (range 50.4-66Gy). The median follow-up period for the survivors was 71months (range 8-175months). The 5-year overall survival (OS) and progression-free survival rates were 54 and 43%, respectively. The 5-year OS rates for stages I-II and III-IV were 67 and 42%, respectively. Recurrence occurred in 29 patients (45%), and recurrence of regional LNs only occurred in 2 patients (3%). Grade 3 or higher late adverse events were observed in 8 patients (12%). Grade 5 heart failure occurred in two patients (3%); both had cardiovascular disease before treatment. The long-term results of definitive CRT with ENI for resectable LA-ESCC were favorable. ENI with a 3D planning system may reduce regional LN recurrence and late adverse events.

Clinical analysis of three-dimensional surgical planning system for guiding robot-assisted selective artery clamping partial nephrectomy in completely endophytic renal tumor

Objective: To examine the safety and feasibility of three-dimensional (3D) surgical planning system for guiding robot-assisted selective artery clamping partial nephrectomy (RASPN) in completely endophytic renal tumor. Methods: Clinical data of 32 patients who suffered from completely endophytic renal tumor and underwent RASPN associated with 3D surgical planning system in Department of Urology, Sun Yat-Sen University Cancer Center from November 2018 to August 2021 were analyzed retrospectively. There were 21 males and 11 females, with the age (M (IQR)] of 45.0 (17.5) years (range: 30 to 68 years). Fifteen tumors were located on the left and 17 on the right. Maximum tumor diameter, R.E.N.A.L. Score and preoperative estimated glomerular filtration rate (eGFR) were 27.5 (13.0) mm (range: 14 to 50 mm), 10.0 (1.8) (range: 7 to 11), and 105.5 (15.7) ml·min-1·(1.73 m2)-1 (range: 71.1 to 124.8 ml·min-1·(1.73 m2)-1), respectively. The 3D reconstruction before RASPN was performed in all patients to formulate surgical planning, mainly including stereo localization of renal mass, confirmation of tumor feeding artery, and injury prediction of collecting system or vessel via "2 mm distance method" defined as probable damage of renal pelvis/calyx and artery/vein when these tissues were less than 2 mm away from tumor. Results: Totally 32 patients successfully underwent RASPN guided by 3D surgical planning system, without conversion to open operation or radical nephrectomy. Rapid location of tumor and selective clamping of artery were achieved in all cases and no one encountered global ischemia, with branch occlusion time of 24.5 (15.4) min (range: 12 to 60 min) and coincidence rate of 95.0% (57/60) between planned and actual clamping vessels. The sensitivity and specificity of 2 mm distance method for predicting the injury of collecting system were 13/15 and 17/17, respectively. The operating time of 185 (48) minuetes (range: 76 to 295 minutes) and estimated blood loss of 200 (350) ml (range: 20 to 800 ml) were observed, without intraoperative transfusion case. There was one patient performed with renal vein repair. Clavien-Dindo postoperative grade Ⅱ and Ⅲa bleeding complications occurred in 2 cases, and no postoperative urinary fistula was found. The length of hospitalization was 3 (0) days (range: 2 to 10 days). The pathological diagnosis demonstrated 4 chromophobe cell carcinomas and 2 angiomyolipomas, besides 26 clear cell carcinomas including one positive surgical margin. The postoperative latest eGFR was 103.9(18.5) ml·min-1·(1.73 m2)-1 (range: 75.8 to 122.3 ml·min-1·(1.73 m2)-1) and no tumor recurrence or metastasis was detected during the follow-up time of 15.4 (13.9) months (range: 3 to 35 months). Conclusion: For RASPN in completely endophytic renal tumor, 3D surgical planning system is contributed to determining mass position, defining tumor feeding artery, and predicting collecting system/vessel injury, which benefited precise tumor resection, postoperative renal function preservation, and perioperative urinary fistula and bleeding complication decrease.

Comparison of percutaneous microwave ablation and surgical resection for hepatocellular carcinoma in the caudate lobe.

This study aims to compare the clinical efficacy and safety between ultrasound (US)-guided percutaneous microwave ablation (MWA) assisted with a three-dimensional (3D) visualization preoperative planning system and surgical resection (SR) for hepatocellular carcinoma (HCC) in the caudate lobe. Forty-nine patients diagnosed with caudate lobe HCC, who underwent US-guided percutaneous MWA (29 patients) or SR (20 patients), were enrolled between November 2005 and December 2018. Follow-up was performed at 1, 3, 6, 12, 18, 24, and 36 months after ablation or resection. The follow-up endpoint was recurrence or patient death. Overall survival (OS) and progression-free survival (PFS) were the primary outcomes, whereas local tumor progression (LTP), intrahepatic recurrence, and extrahepatic metastasis were the secondary ones. The mean age of the two groups was 61.4 ± 9.1 (MWA) and 53.1 ± 6.8 (SR), respectively, with a significant difference (P < 0.01). There were no significant differences in OS (69.0% in the MWA group and 75.0% in the SR group) and PFS (62.1% in the MWA group and 35.3% in the SR group). LTP, intrahepatic recurrence, and extrahepatic recurrence were 6.9% (2/29), 31.0% (9/29), and 20.7% (6/29) in the MWA group and 5.0% (1/20), 60.0% (12/20), and 5.0% (1/20) in the SR group. The MWA group was more cost-effective and required less hospitalization time. No major complications were observed. US-guided percutaneous MWA for HCC in the caudate lobe assisted with a 3D visualization preoperative planning system is an optional treatment with less expenses and shorter hospitalization than SR.

The "STARS" study: advanced preoperative rehearsal and intraoperative navigation in neurosurgical oncology.

Neurosurgical 3D visualizers and simulators are innovative devices capable of defining a surgical strategy in advance and possibly making neurosurgery safer by rehearsing the phases of the operation beforehand. The aim of this study is to evaluate Surgical Theater™ (Surgical Theater LLC, Mayfield, OH, USA), a new 3D neurosurgical planning, simulation, and navigation system, and qualitatively assess its use in the operating room. Clinical data were collected from 30 patients harboring various types of brain tumors; Surgical Theater™ was used for the preoperative planning and intraoperative 3D navigation. Preoperative and postoperative questionnaires were completed by first and second operators to get qualitative feedback on the system's functionality. Furthermore, we measured and compared the impact of this technology on surgery duration. Neurosurgeons were overall satisfied when using this rehearsal and navigation tool and found it efficient and easy to use; interestingly, residents considered this device more useful as compared to their more senior colleagues (with significantly higher scores, P<0.05), possibly because of their limited anatomical experience and spatial/surgical rehearsal ability. The length of the surgical procedure was not affected by this technology (P>0.05). Surgical Theater™ system was found to be clinically useful in improving anatomical understanding, surgical planning, and intraoperative navigation, especially for younger and less experienced neurosurgeons.

Threedimensional, CT-assisted preoperative planning for primary total hip arthroplasty

Purpose: In hip arthroplasty, exact positioning of the implants is imperative. Preoperative planning is essential to achieve this and is generally conducted using conventional radiographs. The objective of our study was to examine the clinical feasibility of a 3D planning system. Methods: In 500 patients (average age 72.8 (31-87) years), a CT was performed preoperatively for 3D planning. The data were further processed in DICOM format on an external workstation for 3D planning, with the aid of special software (SYMBIOS® 3D-Hip Plan), whereby an exact presentation of the acetabulum and femur was possible in all three planes. The clinical outcome was documented by using the Harris Hip Score. Results: In 470/500 patients (94%), the acetabular cup was successfully implanted as planned. In the area of the stem, in 10/500 patients (2%) a custom made stem was implanted, as adequate treatment due to anatomical reasons could not have been achieved here. Overall, the stem planning could be implemented exactly in 475/500 patients (95%). The neck length of the head was implemented as planned in 465/500 patients (93%). The Harris Hip Score improved from a preoperative average of 47.6 to 70.6. Conclusion: 3D hip planning enables a preoperative simulation of implant positioning, which makes it possible to optimally determine and reconstruct the centre of hip rotation. Potential difficulties that might arise intraoperatively can already be identified preoperatively. Patients who require a custom made stem can be reliably identified.

OD60 - Development and validation of a 3D neutron therapy planning system for FRM 2

OD60 - Development and validation of a 3D neutron therapy planning system for FRM 2

Reducing Breast Treatment Planning Process Time With Automated Script-Based 3D Planning

At our institution, breast radiation therapy planning is performed with electronic compensation technique to maximize dose uniformity within the treated volume. While this technique often provides ideal results, it is labor intensive and dependent on planner skill. At our institution, we initiated efforts to streamline this process in 2017. The purpose of this work was to retrospectively assess the impact of using a script to automate the 3D breast treatment planning process. From January-June 2018, planners manually recorded time from image importation into TPS and the time of treatment plan approval by a physician in order to estimate the overall process time. In December 2018, we implemented automated scripting-based breast treatment planning. For the automated planning process, the same two time points as were previously manually recorded were automatically extracted from January-December 2019. We calculated the total working business hours between initiation of planning and completion of planning paperwork for breast or chest wall treatment with (N+) or without nodal (N-) involvement. Data for the manual planning process included 22 N+ plans and 65 N- plans. Data for the automated planning included 27 N+ plans and 128 N- plans. A single run of the script generated a satisfactory isodose plan in most cases. Treatment planners were able to modify field angles, beam energy and assess the need for deep inspiration breath hold more efficiently using script-based planning. Automation resulted in decreased average overall process for N+ plans from 69.6 (95% CI 54.1,85.2) to 51.3 (44.1, 58.6) hours (two-sample t-test with p-value 0.03) representing a 35.6% decrease; N- plans decreased from 49.2 (42.0,56.4) to 34.5 (30.7, 38.3) hours (two-sample t-test with p-value 0.0005) representing a 41.5% decrease. Utilizing an automated script-based 3D planning system has led to a significant reduction in overall effort and treatment planning process time for breast radiotherapy with and without nodal involvement.

Can 3D surgical planning and patient specific instrumentation reduce hip implant inventory? A prospective study

BackgroundModern designs of joint replacements require a large inventory of components to be available during surgery. Pre-operative CT imaging aids 3D surgical planning and implant sizing, which should reduce the inventory size and enhance clinical outcome. We aimed to better understand the impact of the use of 3D surgical planning and Patient Specific Instrumentation (PSI) on hip implant inventory.MethodsAn initial feasibility study of 25 consecutive cases was undertaken to assess the discrepancy between the planned component sizes and those implanted to determine whether it was possible to reduce the inventory for future cases. Following this, we performed a pilot study to investigate the effect of an optimized inventory stock on the surgical outcome: we compared a group of 20 consecutive cases (experimental) with the 25 cases in the feasibility study (control). We assessed: (1) accuracy of the 3D planning system in predicting size (%); (2) inventory size changes (%); (3) intra and post-operative complications.ResultsThe feasibility study showed variability within 1 size range, enabling us to safely optimize inventory stock for the pilot study. (1) 3D surgical planning correctly predicted sizes in 93% of the femoral and 89% of the acetabular cup components; (2) there was a 61% reduction in the implant inventory size; (3) we recorded good surgical outcomes with no difference between the 2 groups, and all patients had appropriately sized implants.Conclusions3D planning is accurate in up to 95% of the cases. CT-based planning can reduce inventory size in the hospital setting potentially leading to a reduction in costs.

Development of three-dimensional preoperative planning system for the osteosynthesis of distal humerus fractures

BackgroundTo reproduce anatomical reduction and appropriate implant placement/choices during osteosynthesis for elbow fractures, we developed a 3D preoperative planning system. To assess the utility of 3D digital preoperative planning for the osteosynthesis of distal humerus fractures, we evaluated the reproducibility of implant reduction shapes and placements in patients with distal humerus fractures.MethodsTwelve patients with distal humerus fractures who underwent osteosynthesis using 3D preoperative planning were evaluated. Reduction shapes were evaluated by the angle between the diaphysis axis and a line connecting the vertices of the medial epicondyle and the lateral epicondyle (epicondyle angle), and the angle between the diaphysis axis and the articular surface (joint angle) in the coronal plane, and the distance between the anterior diaphysis and the anterior articular surface in the sagittal plane (anterior distance) based on 3D images of the distal humerus. In addition, the implant positions were evaluated by the positions of the proximal and posterior edge of the plate, and the angle of the plate to the epicondyle line. The reproducibility was evaluated by intra-class correlation coefficients of the parameters between pre- and postoperative images.ResultsThe intra-class correlation coefficients were 0.545, 0.802, and 0.372 for the epicondyle angle, joint angle, and anterior distance, respectively. The differences in the measurements between the preoperative plan and postoperative reduction were 2.1 ± 2.1 degrees, 2.3 ± 1.8 degrees, and 2.8 ± 2.0 mm, for the epicondyle angle, joint angle, and anterior distance, respectively. The intra-class correlation coefficients were 0.983, 0.661, and 0.653 for the proximal and posterior plate positions, and the angle to the epicondyle, respectively. The differences in the measurements between the preoperative plan and postoperative reduction were 3.3 ± 2.1 mm, 2.7 ± 1.7 mm and 9.7 ± 9.8 degrees, for the plate positions of proximal and posterior edge, and the angle of the plate to the epicondyle line, respectively. There were significant correlations for the epicondyle angle, joint angle, and plate positions.Conclusions3D preoperative planning for osteosynthesis of distal humerus fracture was reproducible for the reduction shape of the coronal view and the plate positions. It may be helpful for acquiring practical images of osteosynthesis in distal humerus fractures.Level of evidenceLevel III, a case–control study.

Preliminary exploration of 3D printed individualized applicator for 3D-image-guided intracavitary HDR-brachytherapy for nasopharyngeal carcinoma

Objective To explore the feasibility of 3D printed individualized applicator for the intracavitary HDR-brachytherapy for nasopharyngeal carcinoma. Methods CT scan was performed in 1 case of recurrent rT1 nasopharyngeal carcinoma and 1 case of T2 residual nasopharyngeal carcinoma and the obtained images were transmitted to 3D image processing software. The geometric contour parameters of the nasopharyngeal cavity were obtained and a pipeline was designed to make it close to the recurrent gross tumor volume (rGTV). Individualized cavity applicators were created by using 3D printer. The applicator was inserted into the patient′s nasopharyngeal cavity through oral cavity. The source tube and false source were inserted into the preset pipe of the applicator. CT scan was performed again and the images were transmitted to the 3D brachytherapy planning system. After delineating the target volume and organ at risk, treatment plan was optimized. After completing the first treatment, the applicator was removed. Before second treatment in a few days, CT scan was reviewed to confirm whether the position was correct. Results When the applicator was inserted into the nasopharyngeal cavity, it could be fully aligned with the nasopharyngeal wall and self-fixed without additional fixation measures. Comparing the location of false source in multiple reviews of CT scan, the error was ≤1 mm. No significant discomfort was reported throughout the treatment. In optimized three-dimensional treatment, 100% prescription dose curve included the full rGTV, maximum dose of the brain stem and spinal cord was<30% prescription dose. Recurrent patients were given with a prescription dose of DT 40Gy/8 fractions/4 weeks and patients with residual tumors were given with 12Gy/2 fractions/1 week. No tumor recurrence was observed at postoperative 3 months in two cases. Conclusions The 3D printed individualized nasopharyngeal intracavitary applicator has the advantages of self-fixation, accurate location, good repeatability and good patient tolerance. The short-term outcome is effective, whereas its long-term clinical effect and adverse reactions need to be further observed. Key words: 3D printed; Individualized applicator; Nasopharyngeal neoplasm/intracavitary radiotherapy

3D visualization ablation planning system assisted microwave ablation for hepatocellular carcinoma (Diameter >3): a precise clinical application

BackgroundThe aim of this retrospective study was to compare the feasibility and efficiency of ultrasound-guided percutaneous microwave ablation (US-PMWA) assisted by three-dimensional visualization ablation planning system (3DVAPS) and conventional 2D planning for hepatocellular carcinoma (HCC) (diameter > 3 cm).MethodsOne hundred thirty patients with 223 HCC nodules (5.0 ± 1.5 cm in diameter, [3.0–10.0 cm]) who met the eligibility criteria divided into 3D and 2D planning group were reviewed from April 2015 to August 2018. Ablation parameters and oncological outcomes were compared, including overall survival (OS), recurrence-free survival (RFS), and local tumor progression (LTP). Multivariate analysis was performed on clinicopathological variables to identify the risk factors for OS and LTP.ResultsThe median follow-up period was 21 months (range 3–44). Insertion number (5.4 ± 1.2 VS. 4.5 ± 0.9, P = 0.034), ablation time (1249.2 ± 654.2 s VS. 1082.4 ± 584.7 s, P = 0.048), ablation energy (57,000 ± 11,892 J VS. 42,600 ± 10,271 J, P = 0.038) and success rate of first ablation (95.0% VS. 85.7%, P = 0.033) were higher in the 3D planning group compared with those in 2D planning group. There was no statistical difference in OS, and RFS between the two groups (P = 0.995, P = 0.845). LTP rate of 3D planning group was less than that of 2D planning group (16.5% VS 41.2%, P = 0.003). Multivariate analysis showed tumor maximal diameters (P < 0.001), tumor number (P = 0.003) and preoperative TACE (P < 0.001) were predictors for OS and sessions (P = 0.024), a-fetoprotein level (P = 0.004), and preoperative planning (P = 0.002) were predictors for LTP, respectively.Conclusions3DVAPS improves precision of US guided ablation resulting in lower LTP and higher 5 mm-AM for patients with HCC lesions larger than 3 cm in diameter.

Considerations and adaptions to the modulated arc total body irradiation technique: dosimetry description.

Total body irradiation (TBI) is a complex treatment technique, which has been slow to transition to a three‐dimensional (3D) planning approach. There is limited literature available providing a detailed description on methods to plan TBI on a 3D planning system. 3D planning using the modulated arc TBI (MATBI) technique is a complex process involving a significant number of quality assurance processes and scripts, due to more than 40 treatment beams and two patient positions. This article will focus on the workflow and technical planning aspects of our institution’s MATBI technique and identify reasons for modifications made to the developing institution’s original MATBI approach. Included is a description of specific simulation equipment, detailed explanation of the four‐stage computing process including the role of scripting to standardise and streamline what is otherwise a complex number of steps. The information provided is specific to one centre’s approach but shows the fundamental planning process and demonstrates a streamlined method, which can be adapted to other planning systems. Overall, the ability to accurately represent the TBI technique in 3D on a planning system will be shown.

P2.04-87 Efficacy of Immune Checkpoint Inhibitors for Locally Advanced Non-Small Cell Lung Cancer Patients Before Durvalumab Approval

Standard treatment for patients with locally advanced (LA) non-small cell lung cancer (NSCLC) was concurrent chemoradiotherapy (CRT) with 40-70% of 2-year overall survival (OS). Immune checkpoint inhibitors (ICIs) have been shown efficacy in advanced or recurrent NSCLC and approved on December 2015 in Japan. After that, the ICI durvalumab was approved as maintenance therapy after concurrent CRT even in unresectable LA-NSCLC on July 2018 in Japan. To investigate the feasibility of concurrent CRT for LA-NSCLC patients and efficacy of ICI treatment for the relapsed patients after CRT, we assessed consecutive LA-NSCLC patients treated with concurrent CRT between July 2013 and June 2018 (before durvalumab approval), retrospectively. 108 eligible patients (81 males and 27 females with median age of 65 years old, including 7 patients with targeted mutations; 2 EGFR, 4 ALK and 1 ROS1) were analyzed. All patients received radical thoracic radiotherapy using 3D planning system and concurrent with platinum-based chemotherapy. 79 (73%) received one or two cycles of consolidation chemotherapy of same regimen. 105 (97%) patients completed planned radiotherapy, and radiation pneumonitis was observed in 93 (85%) patients with median 130 (range, 41-317) days from initiation of radiation to onset. 74 (69%) patients met the PACIFIC criteria and were considered to be eligible for durvalumab. The overall response rate was 64% and the progression free survival was 10.3 (95% CI, 8.4–12.2) months. The OS was 41.8 (95%CI, 20.1-63.5) months and 2-year OS were 63%. Of the 82 patients who relapsed after CRT, 18 patients received ICI treatment (14 nivolumab, 3 pembrolizumab, 1 atezolizumab) in the course of treatment. Patients who received ICI after relapse had significantly better survival than those who did not receive ICI (2-year OS, 87% vs. 41%; p=0.001). Concurrent CRT using platinum-based regimen was considered effective treatment with acceptable toxicity for LA-NSCLC patients. The efficacy of ICI treatment has been shown in patients with relapse after concurrent CRT in LA-NSCLC, and indication with durvalumab maintenance therapy is expected to further improve the prognosis in patients with LA-NSCLC. The optimal use timing of ICI treatment for patients with LA-NSCLC should be considered.